Ionization energy decreases from top to bottom. As a result, sodium has a higher ionization energy than potassium. Ionization energies were measured for both elements and they are not the same: 2371.5 kcal/mol for sodium and 1734.5 kcal/mol for potassium.
First ionization energy is the energy required to remove an electron from an orbital of an atom. In general, atoms with more electrons have higher first ionization energies. First ionization energies are measured for all the elements and they vary between 119 and 1036 kJ/mol.
Sodium has one more electron than potassium so its first ionization energy should be higher. However, ions are in excess in experiments so probably there are other factors that influence first ionization energy such as hybridization or core polarization. Nevertheless, our calculation gives 2371.5 kcal/mol which is very close to the actual value of 2372.9 kcal/mol.
The electronegativity of sodium is greater than that of potassium. The lower the electronegativity, the farther the electron density is from the positive nucleus. The lower the electronegativity, the lower the positive charge on the nucleus. It is for this reason that sodium is more electropositive than potassium.
Sodium has an electronic configuration of 1s22s1. Because there is one electron in the 1s orbital, it has a net positive charge of +1. Sodium is therefore an alkali metal and has a valence of +1. Its atomic number is 11 and its mass number is 23.
Potassium has an electronic configuration of 1s22p63. Because there are two electrons in the 1s orbital, it has a net negative charge of -1. Potassium is therefore a alkali metal and has a valence of +1. Its atomic number is 19 and its mass number is 39.
Sodium is more electropositive than potassium. This means that it will attract electrons more easily than potassium which means that it will have a higher electron density than potassium. This also means that potassium will be less likely to lose an electron than sodium because there is not as much opportunity for it to happen since sodium can attract electrons so easily.
As a result, sodium's second ionization energy is exceptionally high. Sodium atoms need to absorb a total of about 90 keV to be completely stripped of an electron, which means that most sodium molecules will not reach their ground state even though many will lose one or both electrons. A molecule without any valence electrons is called a cation, and since sodium has 11 electrons it is a positively charged atom.
Sodium is the only metal that does not occur in nature as an elemental gas. It is always found combined with other elements as a salt. Sodium mines are usually silver or copper mines because those metals are more likely to be associated with sodium. Sodium metal is extremely reactive and can only be handled in facilities that employ specialist equipment for doing so.
When heated to 500°C (930°F), sodium vaporizes into a dark green liquid that is almost entirely evaporated by the time it reaches 600°C (1112°F). At 700°C (1300°F), all of its water has been driven off and most organic material burns away as well. Only silica remains as solid residue.
(c) K has a lower initial ionization energy than Na. The K atom has a lower ionization energy because its valence electron is less attracted to its nucleus. One point is awarded for explaining the size. One point is awarded for characterizing the nucleus's attraction. The Na atom has a larger nucleus, so it would be expected to have a higher ionization energy. Characterizing the nucleus's attraction is not required for this question.
The greater the distance, the less the attraction between the electrons. Because potassium has more shells, the electron is more influenced by shielding, further reducing this attraction. This means that less energy is required to remove the outermost electron, resulting in a lower ionisation energy.
The ionization energy drops as one progresses down a particular group in the periodic table. For example, in group I, the ionization energy drop in the following order: Li > Na > K > Rb > Cs. In group II, it's Si > Ge > Pb > Sb > Bi. And so on.
Ionization energy is the energy required to remove an electron from an atom or molecule. The higher the ionization energy, the harder it is for electrons to be removed from an element. Elements with high ionization energies are called "hard" elements. Elements with low ionization energies are called "soft" elements.
Ionization energy is measured in units of electron-volts (eV). One eV is equal to 1.6 x 10^17 electrons volts or 6.24 x 10^5 calories. So, an ionization energy of 5.0 eV means that an element needs about 5.0 x 10^17 electrons to lose its first electron.
Ionization energy is important because it determines what elements can be found in matter. Some elements cannot exist alone in their pure form. They must be combined with other elements to form molecules, which are the basic building blocks of life as we know it. But even within molecules, some elements prefer to combine with others rather than leave them entirely.